1. Field of the Invention
The present invention relates to an image filing method and an image filing apparatus for storing image data in a recording medium such as a hard disc and to a program that causes a computer to execute the image filing method.
2. Description of the Related Art
As one form of digital photograph service, network photograph service systems are known. In a network photograph service system, digital images owned by users are stored in an image server and printing orders or the like are received via a network such as the Internet.
In such a system, when registration of digital images is requested from a laboratory at the time of film development or the like, images recorded on a film are read by a film scanner and stored in an image server as digital image data. The image data can be viewed on a network. Moreover, image data obtained by digital cameras can also be stored in the image server. A user can receive various kinds of services such as browsing through the images that have been registered or placing a printing order regarding the images, by accessing the system of a service provider via the network.
Meanwhile, an image data set stored in an image server can be linked to a Web page generated by a user. In this manner, the image data set can be accessed via the Web page according to a function of Web browser software.
Each image server that stores image data sets has a limited image-data storage space. Therefore, in the case where the space would become fully used if an image data set were newly stored in the image server, some of the image data sets that have already been stored therein need to be deleted. For this reason, an image data storing method has been proposed (Japanese Unexamined Patent Publication No. 2(1990)-263269). In this method, a storage period is specified for each image data set. An image data set whose storage period has expired is compressed at a high compression rate to be stored in another recording medium while being deleted from an image server.
In the case where an image data set stored in an image server is linked to a Web page as has been described above, the image data set cannot be referred to from the Web page when the image data set is deleted from the image server. Therefore, Web browser software displays an error message such as “File Not Found”. In this case, if a person in charge of managing the Web page manages the storage period or expiration date for the image data set, the link can be changed or a message indicating deletion of the image data set can be shown in the Web page, for example. However, if the person is not aware of the storage period or the expiration date, the error message “File Not Found” continues to be displayed, which is not preferable. For this reason, it can be proposed to continuously store each image data set in the image server. However, due to the limited image-data storage space, the storage space cannot be increased and eventually, a new image data set cannot be stored in the image server if the existing image data sets remain.